In memory of his mother Penny, who died of cancer in August 2023, all proceeds of the album are going to World Child Cancer, a charity helping children in developing countries to beat cancer.
​
‘Penelope’ features Billy’s new chamber jazz group, Grande Família, both as a 12-piece ensemble and in smaller combinations, interspersed with intimate solo guitar vignettes.
​
The album launch gig was at Pizza Express Jazz Club Soho on 13th May 2024, selling out over two months in advance. This was followed by a sold-out Vortex gig and performance on the Puppet Theatre Barge which sold out over 6 weeks in advance. 
​​
"An exhilaratingly original sound, at once intimate and expansive" 
★★★★ Editor's Choice in JAZZWISE (UK)
​
JAZZWISE review of Grande Família playing "Penelope" live at a sold-out Vortex Jazz Club, 13th Sept 2024:
"An intensely personal insight into Marrows’ unique musical mind"​​​
"The wider band was comprised of big characters and full of improvisational flair"​
"The overall result was raw and emotionally engaging"
​
"The album is a triumph...with his Grande Família project, Marrows has created a spectacular new ensemble"
Jazz Views (UK) 
​
"A highly successful fund raising venture the album is also an impressive musical achievement in its own right. The music coheres remarkably effectively with Marrows himself the unifying force"
★★★★ The Jazz Mann (UK)
​
"What I really like about the album is how its 10 separate pieces, for all their variety of means and approach, behave as though they belong together, like a family"
Richard Williams, The Blue Moment
​
"Melodic and distinctive...an album of inventive and
contemporary chamber-jazz that serves as a worthy tribute and aids a worthy cause" 
★★★★ All About Jazz
​
"Gorgeous chamber jazz LP"
Bandcamp, New and Notable (US)